1. Field of the Invention
The present invention relates to a printing apparatus and a control method therefor.
2. Description of the Related Art
Generally, a printing apparatus is connected to a host apparatus (e.g., PC (personal computer)), and forms an image on a printing medium according to print data from the host apparatus, thereby performing printing. Data that is not print data is also exchanged between the printing apparatus and the host apparatus for achieving improved operability, effective operation of the printing apparatus, and the like.
For example, information for managing the printing apparatus (e.g., status information and remote setting information) and print history information for, for example, calculating the cost of print operation (e.g., information including the amount of ink or sheets used, a host that sends a print request, and the like) are exchanged between the apparatuses. Normally, the information is stored in a RAM (random access memory), a non-volatile memory, an HDD (hard disk drive) or the like provided in the printing apparatus.
Generally, a printing apparatus includes a low power consumption mode for reducing the power consumption, in addition to a normal operation mode. In the printing apparatus including such a mode, when no print data has been received from the host apparatus for a certain period of time, the printing apparatus transitions to the low power consumption mode, and thereby reduces the power consumption in the standby state.
In the low power consumption mode, the power consumption is reduced by stopping supply of power to the units of the printing apparatus (e.g., a CR motor, a LF motor, other motors, various sensors, an inkjet printhead, and an HDD), stopping the operation of a control CPU (central processing unit), and the like. Note that an interface control unit (IF control unit) of the printing apparatus for exchanging data with the host apparatus is controlled such that the IF control unit can exchange print data and other data with the host apparatus, even after the printing apparatus has transitioned to the low power consumption mode. When print data is received in the low power consumption mode, the printing apparatus returns to the normal operation mode due to the notification from the IF control unit, and performs a print operation. When data that is not print data is exchanged, the printing apparatus once returns only units necessary for that data exchange (e.g., a CPU, a RAM, a non-volatile memory and an HDD) to the operation state due to a notification from the IF control unit. Then, after communication with the host apparatus ends, the printing apparatus stops the returned units again.
In the case of a printing apparatus capable of connecting a network, it is necessary to exchange data with a plurality of host apparatuses connected to the network. When a large number of host apparatuses are connected, the above-described data exchange is often performed, and thus the efficiency in reducing the power consumption of the printing apparatus is not improved so greatly. That is, when a large number of host apparatuses are connected, data exchange with the host apparatuses often occurs. Accordingly, even if the printing apparatus transitions to the low power consumption mode, the units of the printing apparatus necessary for data exchange are in the operation state for a long period of time, so that the efficiency in reducing the power consumption deteriorates. In particular, in a printing apparatus including an HDD, if transition between the operation state and the low power consumption mode is often performed, deterioration in the efficiency in reducing the power consumption is remarkable due to an increased number of times the HDD is turned on and off. This is because a large amount of power is consumed in the spinup operation performed when the HDD is turned on.
Also, the number of times the HDD is turned on and off has a close relation to the product life of the HDD, in terms of durability of the head (the number of times the head can be loaded and unloaded). An increase in the number of times the HDD is turned on and off influences the product life of the HDD.
In Japanese Patent Laid-Open No. 2006-215686, a technique is disclosed in which the power consumption is continuously suppressed during the low power consumption mode. With this technique, when the printing apparatus has transitioned from the normal operation mode to the low power consumption mode, a status monitor of the host apparatus stops a polling action to the printing apparatus. Also, the status monitor of the host apparatus restarts the polling action when the printing apparatus has transitioned from the low power consumption mode to the normal operation mode.
As described above, data that is not print data is also exchanged between the printing apparatus and the host apparatus. Such data exchange is performed irrespective of whether the printing apparatus is in the normal operation mode or the low power consumption mode.
The printing apparatus is required to cause the units necessary for data exchange such as the CPU, the RAM and the HDD to transition to the operable state in order to return from the low power consumption mode and perform the data exchange. For this reason, particularly in printing apparatuses capable of exchanging data with a plurality of host apparatuses, the efficiency in reducing the power consumption deteriorates even if it is caused to transition to the low power consumption mode.
In a printing apparatus including an HDD, supply of power to the HDD and stopping of the supply of power are frequently repeated, and the power consumption reduction effect in the low power consumption mode deteriorates due to power consumption by the HDD during the spinup operation. In addition, if supply of power to the HDD and stopping of the supply of power are frequently repeated, the product life of the HDD is shortened.
Here, not only the status information from the status monitor, but also various types of data are exchanged between the printing apparatus and a host apparatus. Examples of such data exchange include data exchange according to the printer MIB controlled by the OS of the host apparatus, exchange of print history information performed by device agents. For this reason, with the method in which all polling actions from the host apparatus are stopped unconditionally, as with the above-described technique disclosed in Japanese Patent Laid-Open No. 2006-215686, various types of problems may occur.